Power boat



L, A. DUMAIEFF.

POWER BOAT.

v APPLICATION FILED APH. I8, 1921. L gjljg-@O v www@ Apr. I, E922;

3 SHEETS-SHEET I.

JNVENTOR.

L. A. DUNAJEFF.

POWER BOAT.

APPLICATION mm APR.18,1921.

Patented Apr. E18, E922;

3 SHEETS-SHEET 2.

EQ. C?

L. A. DUNIEFFII POWER BOAT.

APPLICATION FILED APR. III. I92I.

l ,41298480 Patented Apr. 1&8? i922.

S-SHtETShSHEET 3.

LENIU A. DUNAJEFF, Oli Nw YGRE, N. Y.

novum sont?.

LKML Sega Application filed April 18,

T0 all whom 15 may concern;

Be it known that l. Lnoivin A. DUNAJEFF,

`citizen of Russia. and resident of New York,

in the county ot New York and State of New York, have invented certain new end useful Improvements in Power Boats, of which the following is a specification.

My invention relates to power boats reind has a particular reference to the boats designed for a high'speed.

rllhe object or' my invention is to provide ahoat or e ship ot a very lovv resista-nce to its propulsion, so as to obtain 'much higher practical speeds than it Was heretofore possible with other constructions rll`he total resistance tothe host propulsion consists mainly of the following elements:

l. Resistance due to the weiter friction,

i2. Resistance due to the pressure of the water or heed resistance,

3. Resistance due to the formation of waves and streamline currents.,

l. Air resistance. f Y f rdinery hoats have the seme displaceinent at rest and in noot-ion9 end they have consequently a relatively large Wet surface subject to the irictionel resistance and s large hulk oi the hull in the Water producing' large heed ond weve resistences. At high speeds these resistences become so high` that the power required Aloecornes entirely out of proportion with the size ot the boat or ship. The other type oi' boats, celled hydroplanes, slriinniinfr or surisce" hosts. is distinguished by e more or less flat bottoni set at an :ingle tothe line of inotion., the hull heine" so proportioned that with the higher si'ieeds a lifting; force is pro! duced which tends to raise the "forward part oi the hull out ol the water thereby reducinnF Aits resistance.

The nurin objection to this arrangement is that the forward exposed portion oi the hulh being; suspended in the nir by the coinhined and opposed actions or the velocity' und gravit); and depending on the angle of incidence of the bottom oi the hoot with the Weiter sui-tace. is apt to change its position with the slightest changes in the iactors mentioned. Comparzitively smsllweves are liable to produce violent oscillations ot the host. l

fit the ssi/ne time, such a position ot the heat requires rtor the submerged portion :i comparatively large engl@ or` inciuslence9 psoe Specification of Letters Patent.,

Potent-ed Aller. its? i932.

1921. Serial No. lg.

ducing a large head resistance which is proportional to the square of the sine of this angle. F or these reasons, for instance, the hydroplane type of construction is not applicable to the ler er ships.

ln my improve boat., l am also using :t substantially fist bottoni set et en :ingle with the line of rnovernent7 so that the velocity will have o vertical or lifting component tending to reise the hull partly out of the water as in hydroplanes. But in rny host its forward portion remains onv the surface of the Water, end only the rear end heconies raised et higher speedsS so that the single oi incidence or the tingle with which the bottom meets the Water level, becomes quite small, even up to e rection of one degree of :t circle, the boat hnost hosting on top of the Witter surface. Consequently at higher speeds the resistences due to the Water pressure. eddy currents7 weve formation. and streamline eiiects hecoine corni'iaran tively small. he frictional resistance would have been large, however., ehnost like in ordinary boats on account oi the large surface of the bottoni remaining on the iva,- ter. ln order to reduce this resistance l in.- trodnce a layer of' the air between the water end the bottom surface of the hout. using' various means to nieintuin und renew this air layer or cushion.

lli/ly construction is especially advente# geous for high powered boats or ships with a very smell operating angle of incidence :it

high speeds, because in such cases. :is it will he hereinafter explained, the stability of the host and its resistance to the oscillations or rolling* become very high. i

Myinvention is more fully described in. the accompanying; specification and drew" ings in Which- Fig. l is an elevation of my host in open ating condition :it high speeds with its rear end partly raised towards the suriece of the water und with e small single of' incidence w.

2 is e crosssection shovvingelso en engine operated blower for forcing' the under the hott-oni of the host. T1ig. 55 is en elevation of the seine hoot et re i, Wiuh 'the rear end fully' submerged. l Je. s e hotY torn view showing longitudinal sir retaining ribs. Fig. is en elevation slsrge ship Fig. 6 is e front vievv of seine, hig. ."6" and Fig. 8 ere views of hydro eirplen with my improved fuselege pontoo Fig. is e curve illustre the vnriotions y paratively large, so thatV my boat is made of the velocity V and of the lifting force F in relation toV the changes of the angle of incidence a. Fi 10 represents a similar curve for an ordinary boat without my improvements. Fig. 11 is an elevation of a modified boat at rest with the forward portion submerged. Fig. 12 is the same in motion. Fig. 13 is a sectional elevation of a length of the submerged portion of the boat.- rlhe bottom surface andthese ribs form a channel 4 for the air. A step 5 may be provided near the front end in order to retain the air at comparatively-slow speeds.- At high speeds the air is forced under the boat, being compressed under the inclined forward portion 6. The ribs 3 may beextended almost to thebo-w, so that they may retain the air even when the boat rides over the waves. rl`he bow is raised above the water to prevent the nosing of the boat under the Waves. But as this raised portion may have a tendency at high speeds to be lifted higher by the air pressure, thus reducing the total submerged length, l am providing a fore deck 7 inclinedvat an opposite angle in such a manner, that the air pressure below and above the deck are balanced, so that the front ridge or step V5 touches the water at all speeds, which condition is important for the proper operation of my boat. Additional guiding planes or ailerons 8 may be provided in order to properly adjust the operating position of the front end of the boat.

lin order lto get full benefit of the air cushlon or layer 4, its width must be comalmost as wide at the front as it is at the rear, and the distance between theI ribs 3 is the same through the length of the boat.

lin order to get the air under the boat. especially at slow speeds, an air blower- 9 may be used, forcing the air through the chan-' nels 10. The weight of the boat is so distributed` that at rest, the rear portion of the boat sinks deeper than the front end until enough water is displaced to support the rllhe angle a is then weight of the boat. comparatively large. but at high speeds a lifting force is developed, tending to raise the hull out of the water, especially its rear portion, thereby ldecreasing the angle (L.

lf the -boatis propelled by an ordinary screw propeller' 11, the same must be placed Large-fie at a proper depth so as not to disturb the air layer 4. y

Additional steps 1Q may be provided at the bottom in order to retain at least a portion of the air, when the boat is rolling and pitching on heavy seas. While the air may be washed from under the bottom by the action of the waves, some of the air will be retained in the inside corners of these steps, and there will be continuous forcing of the air from one step to the other towards the stern.` i

At high speeds, such as may be obtained with my boat, in excess of one hundred miles per hour, for instance,an ordinary screw propeller becomes inefficient so that I prefer to use an airplane type screw propellor 13, as is shown in Figures 5 and 13. An air rudder 14 on the deck is also more efficient than an ordinary water rudder l5.

My hull construction with the air cusl1- ioned bottom may be advantageously applied to-ordinary hydro aeroplanes, as shown in Figures 7 and 8. rlhe main fuselage 49 may be so equipped, and also the end pontoons 50. rlhis arrangement enables lthe aeroplane to rise quicker and to propel itself on the water or to taxi on the water at high speeds.

The boat may be also constructed in such manner, that its forward portion will be im- 'inersed in the water when at rest. as it is .shown in Figures 11 and 12. This arrangement may be useful in case when the boat is propelled by the paddle wheel 16. 'll-he operative position of the hull at a normal speed will be the same relatively as in case of a consti-action shown in Fig. 1.

ln case the boat is equipped withan internal combustion engine. the exhaust gases may be utilized to supply the gaseous layer under the hull, and this arrangement is illustrated in Fig. 13. The exhaust pipe Il" of the engine 18 has an extension pipe 19 with a regulating valve Q0, through which the gases or a portion of them may be di'i verted under the bottoni to the forward portion of the hull. The main exhaust pipe extension 21 also has a valve 22, which must be closed when the gases are directed through the .pipe 19.

.ln order to prevent the gases from escaping when the bow of the boat is raised on the waves. a plate 23 (Figfl) may be employed pivoted at the point 24.. pressure will keep it in a closed position pressed against the hull, but it will drop down7 as it is shown with dotted lines. when the bow is pitched upwards on the waves. so that a certain amount of air will lhe retained under this plate. even if it leaves the water entirely for av moment. rl`his air will be forced under the hull as soon as the boat returns to its normal position` and the platt` swings against the hull.

Figures 9 and 10 represent comparative The water "iso i/iiaeae curves for the air cushioned boat and Ifor the saine boat without any air under the hull. The abscissae correspond to angles of incidence a, and against these abscissae are plotted corresponding values 'for the velocities V and for the lifting force P". rll`he dotted line 25 corresponds to the total weight ot' the boat. rl`he power ot' the motor is supposed to remain constant.

rlhe character'of the curves indicates, that without any air (curve Fig. l0) the boat may become unstable in its movement, as it may have considerable variations of the anerle of incidence with but small variations of the velocity and ot the lifting force, and there may even exist conditions, when for the same lifting `torce there will be two different angles oli incidence. Consequently the boat may swing up and down and batter itself on the water while maintaining its speed. At the same time, if the boat is lieavy,.the lifting force may not be suflicient to raise the boat enough so as to reduce the angle a and consequently to bring the velocity V to the desired high value.

ln case of an air layer under the bottom, the velocity becomes very high (curve Fig. 9), the lifting torce also high, and the boat easily rises to a position, when the angle a becomes very small` as indicated'loy thev points ot intersection 26 and 27. lt is important, however. to have the boat laying on the water with its Jfull length. Abarely touchinga the water with its *forward step 5, because it any considerable portion of the ship hull leaves the water, then the angle immediately increases with a corresponding;` increase of the resistance and decrease of the velocit,v and of the lifting torce.

inspection ot' tliecurve Figure 9 reveals, that when the boat slrims over the water at a very small angle o and with the velocity and littinp torce as indicated by the points 26 and 2T, then the conditions ot stability become extremely -favorable. lndeed, the slightest increase of the angle will be imme-l diately followed by a large increase oi the lifting force. causing the boat to rise and, therefore, reducing' airain the value of the angle a, Consequently the boat will have a strongr tendency to retain its longitudinal angular position, the curves 'from Y and l? being-steep at points near aero angle (r.

ln order to malte, the boat stable on the rolling sea it may be made comparatively wide, because with its small displacement the resistances depend on the total area only and not on the relation ot width to the length. u

rllhe stability may be further .increased by the use ot some well known devices tor this purpose, such as gyroscopic stabilizers.

@n heavy seas the waves may wash out sonic of the air from under the-hull, and in this case the toothed bottom, consisting of numerous steps 12, may be used to the advantage, because sorne of the air will be retained under the teetha Figures 14, 15 and 16 represent a modiied arrangement of my boat, using powerful air blowers 28 in the forward portion of the boat. These blowers supply the air under compression for 'the bottom compartment 4 between the ribs 3. T he .air moves continuously towards the rear ot the boat and comes out from under the stern. The reaction of the expanding air leaving the boat propels the boat forward. The stern is provided with an adjustable extension plate 29 with side ribs or walls 30. The air, moving under this plate, 'forces the water out with equally distributed pressure thereby producing a perfect streamline extension to the boat and reducing the eddy losses in the water.

Additional blowers 3l may be placed near the stern to provide more air Afor the boat propulsion, directing1 this air through the channels B2 under the stern.

rlhe receiving air pipes 33 and 34 are direc'ted against the movement of the boat, so that the air resistance, even at high speeds, is practically eliminated, all of the oncoming,r air being" sucked in by 'the blowers. Exhaust gases 'from motors 35 and 36 are directed by the pipes 3T under the boat. 'No back pressure will be developed in this case, as the moving air will. help to carry the gases rapidly away.

A butterfly valve 39 may be used to regulate the motor speed by regulating the passages 'for the air. ln case ot centrifugal blowers this action will also automatically regulate the load of the motors.

Additional pipes d() mayv be connected to the blowers, directing the air to the forward portion of 'the boat. Valves il ordinarily lreep these pipes closed. Ey openingr these valves and closing valves B9, the How of air `will be diverted towards the Airont end of the boat, thus producingi a 'retardingig or braking effect on its movement.

A similar construction is shown in kFigure 17. `Here the hinged plate 23 covers an opening l2 in the Vliront wall ot the boat, and this opening' is alsoV closed with a sliding' valve- 4:3. An aperture lll in this valve admits the air from the blower under the bottom. By movingr the valve with a pinion-e5 and a rack 4&6, the passage l? becomes closed, and the air pressure, acting` through uncovered aperture e2, moves the plate ivay. rlhe air pressure, being directed 'towards the front end ot the ship., will tend to stop the shi movement.

Il; single blower 25% (Fig. t8) may loe used to supply the air under the bott-om and to propel the boat. For this purpose a portion ot the air is directed through tubular passages 48 on the sides ot the snip towards the stern and under the stern plate llO This method of ship propulsion, consisting in blowing the air under the ship bottom from the bow of the shiptowards the stern, is very efficient and possesses some other advantages, its eficiency being partly due to the compressibility of the air, so that the blowers produce a vacuum in front of the ship and a quantity of a compressed air in the rear. The propelling force is produced partly by this vacuum and partly by the reaction of the compressed and expanding air. The iiow of the air separates the surface of the ship from the water, thereby reducing the frictional resistances. The air resistance is considerably reduced and may be practically eliminated, when all of the crosssectional surface of the ship is utilized for the air intake.

llhis method diders substantially from the known method of ship propulsion by means of the water pumps, drawing the water through special tubes from the forward portion of the ship to the rear. The water, being incompressible, absorbs a considerable amount of the motive power in an inelastic shock and eddies` and the resistance, due to the increased contact surface with the water, is largely increased.

The advantages of my boat and method of propulsion are as follows:

The boat can be propelled at a very high speed with comparatively small expenditure of power, the resistances being greatly reduced, lirst, by the introduction of the air under the bottom, second by the lifting of the boat to the surface of the water.

The boat may be made very large and wide so as to better resist the waves. My construction can be fully applied to the largest ocean going ships.

My boat can navigate very shallow waters.

With my method of propulsion by means of air blowers it is possible to utilize high speed, efcient and light prime movers, such as turbines or Diesel engines.

rlhe exhaust of the internal combustion engines is more fully utilized in my boat.

l claim as my invention:

l. ln a power boat, the combination with a hull, longitudinally arranged ribs under said hull, means to introduce Ia gas under said hull between said ribs, and means to form a gaseous streamline extension back of the stern of said hull. f

terasse direc-ted against the movement of said boat,

an air duct for said blower under said hull, a blower in the aft of said hull, and an air `duct for said aft blower, directed under and aft of said hull.

3. In a power boat, the combination with a hull, longitudinal ribs under said hull, a plurality of substantially flat surfaces between said ribs, means to introduce a layer of compressed gases between said flat surfaces and the water, and a flat extension back of the stern of said hull adapted to receive the excess of gases from under said hull.

4. ln a power boat, the combination with a hull, means to introduce the gases under said hull, and means to form a streamline extension with a quantity of said gases behind said hull in the water.

5'. In a power boat, the combination with a hull, means to introduce gases under said hull, longitudinally arranged ribs under said hull from stern to bow' evenly spaced apart,

means to introduce the air under said hull,l

and means to prevent said air from escaping from under the forward portion of said hull on the -waves in a rough sea.

6. ln a power boat, the combination with a hull, said hull being of approximately the same width from stern to bow,'a plurality of longitudinally arranged ribs under said hull, and a plate in front of said hull hinged above the water and extending under water.

7. ln a power boat, the combination with a hull, a plurality of ribs under said hull. extending above the water on the ends, a plurality of substantially Hat surfaces under said hull and between said ribs, and a plate in front of said hull extending in the water below said hull and hinged above the water between said ribs.

8. lin a power boat, the combination with `a hull, means to introduce gases under saidhull, and a horizontally arranged extension plate back of said hull adapted to retain a quantity of said gases forming an extension` 

